package es.uab.sound;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.KeyEvent;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import es.uab.sound.dao.UsersDao;

/**
 * Activity which displays a login screen to the user, offering registration as well.
 */
public class LoginActivity extends Activity {

	private UserLoginTask mAuthTask = null;
	private String mEmail;
	private String mPassword;

	// UI references.
	private EditText mEmailView;
	private EditText mPasswordView;
	private View mLoginFormView;
	private View mLoginStatusView;
	private TextView mLoginStatusMessageView;
	private Button buttonSign;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_login);

		// Set up the login form.
		mEmailView = (EditText) findViewById(R.id.email);
		mPasswordView = (EditText) findViewById(R.id.password);
		buttonSign = (Button) findViewById(R.id.sign_in_button);
		mLoginFormView = findViewById(R.id.login_form);
		mLoginStatusView = findViewById(R.id.login_status);
		mLoginStatusMessageView = (TextView) findViewById(R.id.login_status_message);

		mEmailView.setText("daperisro@gmail.com");
		mPasswordView.setText("1234");

		mPasswordView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
			@Override
			public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
				if (id == R.id.login || id == EditorInfo.IME_NULL) {
					attemptLogin();
					return true;
				}
				return false;
			}
		});

		buttonSign.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View view) {
				attemptLogin();
			}
		});
	}

	/**
	 * Attempts to sign in or register the account specified by the login form.
	 * If there are form errors (invalid email, missing fields, etc.), the errors are presented and no actual login attempt is made.
	 */
	public void attemptLogin() {
		if (mAuthTask != null) {
			return;
		}

		// Reset errors.
		mEmailView.setError(null);
		mPasswordView.setError(null);

		// Store values at the time of the login attempt.
		mEmail = mEmailView.getText().toString();
		mPassword = mPasswordView.getText().toString();

		boolean cancel = false;
		View focusView = null;

		// Check for a valid password.
		if (TextUtils.isEmpty(mPassword)) {
			mPasswordView.setError(getString(R.string.error_field_required));
			focusView = mPasswordView;
			cancel = true;
		} else if (mPassword.length() < 4) {
			mPasswordView.setError(getString(R.string.error_invalid_password));
			focusView = mPasswordView;
			cancel = true;
		}

		// Check for a valid email address.
		if (TextUtils.isEmpty(mEmail)) {
			mEmailView.setError(getString(R.string.error_field_required));
			focusView = mEmailView;
			cancel = true;
		} else if (!mEmail.contains("@")) {
			mEmailView.setError(getString(R.string.error_invalid_email));
			focusView = mEmailView;
			cancel = true;
		}

		if (cancel) {
			// There was an error; don't attempt login and focus the first form field with an error.
			focusView.requestFocus();
		} else {
			// Show a progress spinner, and kick off a background task to perform the user login attempt.
			mLoginStatusMessageView.setText(R.string.login_progress_signing_in);
			showProgress(true);
			mAuthTask = new UserLoginTask();
			mAuthTask.execute((Void) null);
		}
	}

	/**
	 * Shows the progress UI and hides the login form.
	 */
	@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
	private void showProgress(final boolean show) {
		// On Honeycomb MR2 we have the ViewPropertyAnimator APIs, which allow
		// for very easy animations. If available, use these APIs to fade-in
		// the progress spinner.
		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
			int shortAnimTime = getResources().getInteger(android.R.integer.config_shortAnimTime);

			mLoginStatusView.setVisibility(View.VISIBLE);
			mLoginStatusView.animate().setDuration(shortAnimTime).alpha(show ? 1 : 0).setListener(new AnimatorListenerAdapter() {
				@Override
				public void onAnimationEnd(Animator animation) {
					mLoginStatusView.setVisibility(show ? View.VISIBLE : View.GONE);
				}
			});

			mLoginFormView.setVisibility(View.VISIBLE);
			mLoginFormView.animate().setDuration(shortAnimTime).alpha(show ? 0 : 1).setListener(new AnimatorListenerAdapter() {
				@Override
				public void onAnimationEnd(Animator animation) {
					mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
				}
			});
		} else {
			// The ViewPropertyAnimator APIs are not available, so simply show
			// and hide the relevant UI components.
			mLoginStatusView.setVisibility(show ? View.VISIBLE : View.GONE);
			mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
		}
	}

	/**
	 * Represents an asynchronous login/registration task used to authenticate the user.
	 */
	public class UserLoginTask extends AsyncTask<Void, Void, Boolean> {
		@Override
		protected Boolean doInBackground(Void... params) {
			return new UsersDao().loadByUsername(mEmail, mPassword);
		}

		@Override
		protected void onPostExecute(final Boolean success) {
			mAuthTask = null;
			showProgress(false);
			if (success) {
				Intent myIntent = new Intent(LoginActivity.this, RecordActivity.class);
				startActivity(myIntent);
			} else {
				mPasswordView.setError(getString(R.string.error_generic));
				mPasswordView.requestFocus();
			}
		}

		@Override
		protected void onCancelled() {
			mAuthTask = null;
			showProgress(false);
		}
	}
}
